Rectifying valve

Abstract

To provide a valve with a rectification function capable of increasing cavitation suppression efficiency by stably supplying air from an air supply pipe into a valve box.SOLUTION: A valve with a rectification function comprises: a cylindrical valve box with an inflow pipe connected to an opening part at one axial end side and an outflow pipe connected to an opening part at the other axial end side; a valve body that adjusts the opening at one end side in the valve box; an air supply pipe that supplies air into the valve box; and a rectification member provided inside the valve box. The rectification member is configured to rectify a flow of liquid so that liquid having flowed into the valve box from a gap between the opening part at the one end side and the valve body flows away from a circulation area for air having flowed into the valve box from the air supply pipe.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a valve with a flow rectifying function. [Background technology]

[0002] In a valve used to adjust the flow rate of a liquid in a pipe, when the pressure difference between the upstream and downstream sides is large and the downstream pressure is low, narrowing the opening can cause bubbles to form downstream in the gap between the opening and the valve element that opens and closes the opening (cavitation). Bubbles generated by cavitation can cause erosion, noise, vibration, and the like when they collide with pipes, etc. An example of a valve that can suppress the occurrence of such cavitation is described in Patent Document 1. The valve described in Patent Document 1 is equipped with an air supply pipe that sends air into the valve body. In the valve described in Patent Document 1, the occurrence of cavitation can be suppressed by supplying air from the air supply pipe to an area in the valve body where cavitation is likely to occur. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-150664 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the valve described in Patent Document 1, the flow of liquid that has entered the valve body from between the valve disc and the opening may obstruct the supply of air from the air supply pipe into the valve body. If the supply of air into the valve body is obstructed, the efficiency of suppressing cavitation may decrease.

[0005] In view of these problems, the present invention aims to provide a valve with a rectifying function that can improve the efficiency of suppressing cavitation by stably supplying air from the air supply pipe to the valve body. [Means for solving the problem]

[0006] The valve with straightening function of the present invention comprises a cylindrical valve box having an inlet pipe connected to an opening at one axial end and an outlet pipe connected to an opening at the other axial end, a valve body within the valve box that adjusts the opening of the one end opening, an air supply pipe that supplies air into the valve box, and a straightening member provided within the valve box, wherein the straightening member is configured to straighten the flow of liquid so that the liquid that flows into the valve box through the gap between the opening at the one end and the valve body flows away from the flow area of ​​air that has flowed into the valve box from the air supply pipe. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a valve with a rectifying function that can improve the efficiency of suppressing cavitation by stably supplying air from the air supply pipe into the valve body. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an example of a valve with a rectifying function according to one embodiment of the present invention, showing a state in which an opening on one end side of a valve body is fully closed. [Figure 2] 2 is a cross-sectional view schematically showing an example of a valve with a rectifying function according to one embodiment of the present invention, showing a state in which the opening on one end side of the valve body is slightly opened from the state shown in FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] 4A and 4B are enlarged views of the main parts of a valve with a rectifying function according to one embodiment of the present invention, in which (a) is an enlarged view of the main parts in FIG. 3, and (b) is an enlarged view of the main parts in FIG. 2. [Figure 5] 3 is a cross-sectional view schematically showing an example of a valve with a rectifying function according to one embodiment of the present invention, showing a state in which the opening on one end side of the valve body is further opened from the state shown in FIG. 2. FIG. [Figure 6]6 is a cross-sectional view schematically showing an example of a valve with a rectifying function according to one embodiment of the present invention, showing a state in which the opening on one end side of the valve body is further opened from the state shown in FIG. 5. FIG. [Figure 7] FIG. 1 is a cross-sectional view schematically illustrating an example of a valve with a rectifying function according to one embodiment of the present invention, showing a state in which an opening on one end side of a valve body is fully open. DETAILED DESCRIPTION OF THE INVENTION

[0009] A valve with rectifying function according to one embodiment of the present invention will be described below with reference to the drawings. Note that the embodiment shown below is merely an example, and the valve with rectifying function according to the present invention is not limited to the following embodiment.

[0010] 1 to 7, a valve 1 with a flow rectifying function according to this embodiment (hereinafter also referred to as valve 1) is a valve that can be used when liquid (for example, water) discharged from facilities such as a dam or a plant is released into a river, etc. Valve 1 has a function to adjust the flow rate of high-speed liquid (for example, water flow) discharged from the facilities, and a function to suppress the occurrence of cavitation inside a valve box 2.

[0011] The valve 1 comprises a cylindrical valve box 2, with an inlet pipe 6 connected to an opening 21 at one axial end and an outlet pipe 7 connected to an opening 22 at the other axial end, a valve element 3 that adjusts the aperture of the opening 21 at one end within the valve box 2, an air supply pipe 4 that supplies air AF into the valve box 2, and a rectifying member 5 provided within the valve box 2. The opening 21 at one end is an opening located at the upstream end of the valve box 2 in the direction of liquid flow. The opening 22 at the other end is an opening located at the downstream end of the valve box 2 in the direction of liquid flow.

[0012] Cavitation (a phenomenon in which a liquid vaporizes and generates bubbles when the liquid is in a low-pressure state) is likely to occur when the valve element 3 has the opening 21 on one end partially open, that is, when the opening degree of the opening 21 on one end is intermediate between the fully closed state and the fully open state (hereinafter also referred to as the intermediate opening state). This is because the flow area of ​​the liquid passing through the opening 21 on one end decreases, increasing the flow rate, and the increased flow rate causes a drop in pressure.

[0013] In this specification, the axial direction of the valve box 2 is referred to as the "axial direction" (the direction indicated by reference symbol D1 in FIG. 1), and the direction perpendicular to the axial direction D1 is also referred to as the "axial-orthogonal direction" (the direction indicated by reference symbol D2 in FIG. 1). The axial direction D1 is the direction connecting the center of the opening 21 at one end of the valve box 2 and the center of the opening 22 at the other end. In addition, within the valve box 2, the upstream side in the liquid flow direction is referred to as the "upstream side" (the direction indicated by reference symbol D11 in FIG. 2), and the downstream side in the liquid flow direction is referred to as the "downstream side" (the direction indicated by reference symbol D12 in FIG. 2). In the example shown in FIG. 1, the left side in FIG. 1 is the upstream side D11 in the liquid flow direction, and the right side in FIG. 1 is the downstream side D12 in the liquid flow direction. That is, the liquid flows within the valve box 2 from the left side (upstream side D11) to the right side (downstream side D12) in FIG. 1. 1, 2, and 5 to 7, the up-down direction of the paper surface corresponds to the up-down direction of the valve 1. In FIG.

[0014] The configurations of the valve box 2 and the valve disc 3 are not particularly limited as long as the valve disc 3 can adjust the aperture of the opening 21 at one end of the valve box 2 and thereby adjust the flow rate of liquid flowing into the valve box 2 through the opening 21 at one end. In this embodiment, the valve 1 includes a tubular (e.g., cylindrical) valve box 2 and a valve disc 3 that opens and closes the opening 21 at one end. In this embodiment, the valve disc 3 is configured to rotate around a rotation axis 31 that extends in a direction perpendicular to both the axial direction D1 and a direction (axially orthogonal direction) D2 that is orthogonal to the axial direction D1 of the valve box 2 within the valve box 2. In this embodiment, the valve disc 3 includes a valve body 32 that opens and closes the opening 21 at one end of the valve box 2 by coming into contact with and separating from the opening 21 at one end of the valve box 2, an arm 33 that supports the valve body 32, and a rotation shaft 31 that rotatably supports the arm 33. The rotation shaft 31 is configured to rotate by a rotation drive device (not shown).

[0015] In the example shown in Figure 1, the radial center of the rotating shaft 31 that rotates the valve body 3 is on the axis 23 connecting the radial center of the opening 21 on one end side of the valve box 2 and the radial center of the opening 22 on the other end side, and is eccentric downstream along the axial direction D1 of the valve box 2 relative to the valve body 32 (hereinafter, such eccentricity will also be referred to as primary eccentricity).

[0016] The valve element 3 is not limited to the above-described eccentric valve with primary eccentricity. For example, the valve element 3 may be a secondary eccentric valve in which the radial center of the rotating shaft 31 is not only primary eccentric but also eccentric in the radial direction of the valve box 2 from the axis 23 (hereinafter, such eccentricity will also be referred to as secondary eccentricity). Furthermore, the valve element 3 may be a tertiary eccentric valve in which, in addition to the radial center of the rotating shaft 31 being secondary eccentric, the central axis of the cone that forms the abutment surface of the valve seat provided on the inner peripheral edge of the opening 21 on one end side of the valve box 2 is inclined with respect to the axis 23 of the valve box 2 (hereinafter, such eccentricity will also be referred to as tertiary eccentricity).

[0017] Furthermore, the valve 1 is not limited to an eccentric valve in which the radial center of the rotation axis 31 is eccentric. The valve 1 may be, for example, a valve in which the rotation axis of the valve disc is not eccentric with respect to the opening at one end of the valve body. An example of such a valve is a butterfly valve. The valve 1 may also be another type of valve. For example, the valve 1 may be a valve in which a cylindrical valve disc moves along the axial direction of the cylindrical valve body within the valve body. An example of such a valve is a needle valve. The valve 1 may also be a valve in which a spherical valve disc rotates within a spherical valve body. An example of such a valve is a ball valve.

[0018] In this specification, when the valve disc 3 is in a fully closed state in which the opening 21 on one end side is closed (see FIG. 1), the direction of a line extending from the rotation axis 31 toward the valve body 32 along the axial direction D1 of the valve box 2 is defined as the reference direction D3 of the valve disc 3 (see FIG. 1). In this embodiment, by rotating the valve disc 3 so that the reference direction D3 of the valve disc 3 approaches a state perpendicular to the axial direction D1 (see FIG. 7), the valve disc 3 is moved farthest from the inner periphery (seat) of the opening 21 on one end side, and the opening degree of the opening 21 on one end side is fully opened. In the fully open state, the flow rate of liquid flowing into the valve box 2 from the opening 21 on one end side is maximized.

[0019] Furthermore, when the reference direction D3 of the valve disc 3 is inclined with respect to the axial direction D1 (the inclination angle between the reference direction D3 and the axial direction D1 is greater than 0° and less than 90°) (see FIGS. 2, 5, and 6), the valve disc 3 (specifically, the valve body 32) is spaced from the inner peripheral edge (seat surface) of the opening 21 on the one end side, creating a gap G1 between the valve disc 3 and the inner peripheral edge of the opening 21 on the one end side. When the size of this gap G1 is small, the flow velocity of the liquid passing through the gap G1 increases. This increase in the liquid flow velocity causes a pressure drop, making cavitation more likely to occur. This pressure drop is likely to occur in the region around the valve disc 3, particularly in the region around the valve disc 3 opposite the opening 21 on the one end side (the region on the opening 22 on the other end side). Specifically, this pressure drop is likely to occur in the region around the valve body 32, particularly in the region around the valve body 32 opposite the opening 21 on the one end side.

[0020] In this embodiment, when the opening degree of the opening 21 at one end side is increased from a fully closed state (see FIG. 1 ) to a certain degree (e.g., 25% opening, see FIG. 2 ), the gap G1 between the valve disc 3 and the lower part of the opening 21 at one end side (hereinafter also referred to as the lower gap G11) increases, and the gap G1 between the valve disc 3 and the upper part of the opening 21 at one end side (hereinafter also referred to as the upper gap G12) also increases. The valve disc 3 approaches the upper part of the inner wall surface 242 of the valve box 2. In the example shown in FIG. 2 , the upper gap G12 is smaller than the lower gap G11. The liquid that passes through the upper gap G12 flows through the gap between the valve disc 3 and the upper part of the inner wall surface 242 of the valve box 2 toward the air supply pipe 4. However, a rectifying member 5 is interposed between the valve disc 3 and the air supply pipe 4. Therefore, the liquid that passes through the upper gap G12 flows toward the air supply pipe 4 via the rectifying member 5.

[0021] When the opening of the opening 21 at the one end is increased further than in FIG. 2 (for example, 50%, see FIG. 5), the gap G1 (gap G11) between the valve disc 3 and the lower part of the opening 21 at the one end becomes larger, and the gap G1 (gap G12) between the valve disc 3 and the upper part of the opening 21 at the one end also becomes larger. The valve disc 3 is closer to the upper part of the inner wall surface 242 of the valve box 2 than in FIG. 2. In the example shown in FIG. 5, the upper gap G12 is smaller than the lower gap G11. The liquid that passes through the upper gap G12 flows through the gap between the valve disc 3 and the upper part of the inner wall surface 242 of the valve box 2 toward the air supply pipe 4. However, a rectifying member 5 is interposed between the valve disc 3 and the air supply pipe 4. Therefore, the liquid that passes through the upper gap G12 flows toward the air supply pipe 4 via the rectifying member 5.

[0022] When the opening degree of the opening 21 at one end is increased further than that shown in FIG. 5 (for example, 75%, see FIG. 6), the gap G1 (gap G11) between the valve disc 3 and the lower part of the opening 21 at one end becomes larger, and the gap G1 (gap G12) between the valve disc 3 and the upper part of the opening 21 at one end becomes smaller. The valve disc 3 is closer to the upper part of the inner wall surface 242 of the valve box 2 than in FIG. 5. In the example shown in FIG. 6, the upper gap G12 is smaller than the lower gap G11. The liquid that passes through the upper gap G12 flows through the gap between the valve disc 3 and the upper part of the inner wall surface 242 of the valve box 2 toward the air supply pipe 4. However, a rectifying member 5 is interposed between the valve disc 3 and the air supply pipe 4. Therefore, the liquid that passes through the upper gap G12 flows toward the air supply pipe 4 via the rectifying member 5.

[0023] When the opening of the one-end opening 21 is increased to its maximum opening (100% opening, see FIG. 7 ) from that shown in FIG. 6 , the gap G1 (gap G11) between the valve disc 3 and the lower part of the one-end opening 21 becomes even larger. In the example shown in FIG. 7 , the valve body 32 of the valve disc 3 is retracted upward relative to the entire one-end opening 21. Therefore, the flow rate of liquid flowing from the one-end opening 21 into the valve box 2 is maximized. Furthermore, regardless of the size of the gap G12, almost all of the liquid flowing from the one-end opening 21 into the valve box 2 passes below the valve body 32 of the valve disc 3. Therefore, only a small amount of liquid flowing from the one-end opening 21 into the valve box 2 through the upper gap G12 flows toward the air supply pipe 4.

[0024] The air supply pipe 4 supplies air AF into the valve box 2, thereby suppressing a pressure drop in the liquid inside the valve box 2. Suppressing a pressure drop in the liquid inside the valve box 2 can suppress the occurrence of cavitation inside the valve box 2. In this embodiment, the air supply pipe 4 is connected to a portion of the peripheral wall 24 of the valve box 2 between the valve disc 3 and the opening 22 on the other end side. Connecting the air supply pipe 4 to this portion of the valve box 2 makes it easier to send air AF to the area around the valve disc 3, particularly to the area around the valve disc 3 on the opposite side from the opening 21 on one end side. By sending air AF to this area (an area where cavitation is likely to occur), the air supply pipe 4 can increase the efficiency of suppressing cavitation in the area around the valve disc 3.

[0025] However, there may be cases where the flow of liquid that has flowed into the valve box 2 from the opening 21 on one end side inhibits the supply of air AF from the air supply pipe 4 into the valve box 2. Specifically, there may be cases where the flow of liquid that has flowed into the valve box 2 from the gap G1 between the valve disc 3 and the opening 21 on one end side, particularly the flow of liquid that has flowed into the valve box 2 from the upper gap G12, inhibits the supply of air AF from the air supply pipe 4 into the valve box 2. There may also be cases where the flow of liquid that has flowed into the valve box 2 from the gap G1 (particularly the upper gap G12) inhibits the air AF that has flowed into the valve box 2 from the air supply pipe 4 from being supplied to an area where a drop in liquid pressure is likely to occur.

[0026] The flow rectifying member 5 controls the flow of the liquid described above, and prevents the supply of air AF from the air supply pipe 4 into the valve box 2 and the air AF that has flowed into the valve box 2 from the air supply pipe 4 from being obstructed to an area where a drop in liquid pressure is likely to occur. The flow rectifying member 5 is configured to rectify the flow of liquid LF so that the liquid that has flowed into the valve box 2 from the gap G1 between the opening 21 on one end side of the valve box 2 and the valve disc 3 flows away from the flow area DA of the air AF that has flowed into the valve box 2 from the air supply pipe 4. In other words, the flow rectifying member 5 has a function (hereinafter also referred to as a flow rectifying function) of rectifying the flow of liquid LF so that the liquid that has flowed into the valve box 2 from the gap G1 flows away from the flow area DA of the air AF that has flowed into the valve box 2 from the air supply pipe 4.

[0027] The rectifying member 5 rectifies the flow LF of liquid so that the liquid that has flowed into the valve box 2 from the gap G1 avoids the flow area DA of the air AF that has flowed into the valve box 2 from the air supply pipe 4, thereby ensuring the flow area DA of the air AF within the valve box 2. This prevents the liquid flow from colliding with the air AF that is flowing from the air supply pipe 4 into the valve box 2, and also prevents the liquid flow from colliding with the air AF that has been supplied from the air supply pipe 4 into the valve box 2. Therefore, the supply of air AF from the air supply pipe 4 into the valve box 2 can be stably performed, and the efficiency of suppressing cavitation can be improved.

[0028] In this embodiment, the flow area DA (see FIGS. 2, 5, and 6) is a region that extends from the downstream end 41 of the air supply pipe 4 in the flow direction of the air AF toward the valve disc 3. Alternatively, the flow area DA is a region of the flow path discharged from or passing through the air supply pipe 4 that is inside (closer to the axis of the valve box 2) the inner wall surface 242 of the valve box 2 in the radial direction (axis-orthogonal direction D2) of the valve box 2. In this specification, the "downstream end 41 of the air supply pipe 4 in the flow direction of the air AF" refers to the downstream end of the through hole 241 in the flow direction of the air AF when the air supply pipe 4 is connected to a through hole 241 formed in the peripheral wall 24 of the valve box 2. Therefore, the downstream end 41 of the air supply pipe 4 does not protrude from the inner wall surface 242 of the peripheral wall 24 of the valve box 2 into the internal space of the valve box 2. As will be described later, when a tubular member protrudes into the internal space of the valve box 2 from the downstream end of the through-hole 241 in the flow direction of the air AF, the tubular member can function as a flow straightening member 5.

[0029] The configuration of the flow rectifying member 5 is not particularly limited as long as it has the above-described flow rectifying function. In this embodiment, the flow rectifying member 5 is configured to divide the liquid that has flowed into the valve box 2 from the gap G1 (see FIGS. 2, 5, and 6) between the opening 21 at one end of the valve box 2 and the valve disc 3, into a flow LF1 (see FIGS. 3 and 4(a)) on one side of the flow area DA and a flow LF2 on the other side, at an upstream side D11 in the liquid flow direction relative to the flow area DA. By configuring the flow rectifying member 5 to divide the liquid in this manner, the path of the liquid can be controlled so that the liquid avoids the flow area DA of the air AF. This more reliably prevents the flow of the liquid from colliding with the air AF flowing through the flow area DA and obstructing the flow of the air AF.

[0030] In this embodiment, the flow rectifying member 5 (see FIGS. 2, 3, and 4) has a flow dividing section 51 that divides the liquid that has flowed into the valve box 2 from a gap G1 (see FIGS. 2, 5, and 6) between the opening 21 at one end of the valve box 2 and the valve disc 3, into a flow LF1 on one side of the flow area DA and a flow LF2 on the other side of the flow area DA, on the upstream side D11 in the liquid flow direction. The configuration of the flow dividing section 51 is not particularly limited as long as it has the above-mentioned flow dividing function.

[0031] In this embodiment, the flow diverter portion 51 is configured to protrude radially inward from the inner wall surface 242 of the valve box 2. The flow rectifier member 5 is formed integrally with the inner wall surface 242 of the valve box 2. By forming the flow rectifier member 5 integrally with the inner wall surface 242, it is possible to prevent the flow rectifier member 5 from falling off the inner wall surface 242 even when the liquid flows fast and the flow rectifier member 5 is subjected to a strong force from the liquid. The flow rectifier member 5 may be detachably attached to the inner wall surface 242. By detachably attaching the flow rectifier member 5 to the inner wall surface 242, maintenance and replacement of the flow rectifier member 5 can be easily performed.

[0032] In this embodiment, the flow diverter 51 is configured to widen in a V-shape from the upstream side D11 to the downstream side D12 in the liquid flow direction when viewed from the radial center side of the valve box 2. The flow diverter 51 is configured to protrude radially inward from the inner wall surface 242 of the valve box 2. That is, the flow diverter 51 has two side walls 511 forming a V-shape. The two side walls 511 are configured to form a predetermined angle θ (see FIG. 4(a)) with each other at the apex of the V-shape. The angle θ is set to an angle that enables the flow diverter 51 to perform the above-described flow diverting function. The flow diverter 51 is configured to widen in a V-shape from the upstream side D11 to the downstream side D12, which facilitates separation of the liquid flowing from the upstream side D11 in the flow direction and can prevent the liquid from accumulating upstream of the flow diverter 51 in the liquid flow direction. By preventing the liquid from accumulating, it is possible to prevent the accumulated liquid from impeding the diverted flow of the liquid further upstream. Furthermore, the flow dividing section 51 does not have to be configured to expand in a V-shape as described above, and may be configured, for example, in a U-shape or semicircular shape when viewed from the radial center side of the valve box 2.

[0033] In this embodiment, the side surface 511 of the diverter 51 is configured to curve outward relative to the center line CL of the V-shape from the upstream side D11 to the downstream side D12 in the liquid flow direction (see FIGS. 3 and 4(a)). In this embodiment, the diverter 51 is disposed so that the center line CL of the V-shape of the diverter 51 (the line dividing the diverter 51 symmetrically) passes through the center of the air supply pipe 4. This curved configuration of the side surface 511 of the diverter 51 allows the diverted liquid to flow along the curved surface more outward relative to the center line CL of the V-shape. This promotes the diverting of the liquid. Note that in the example shown in FIGS. 3 and 4(a), the side surface 511 of the diverter 51 is configured flat on the upstream side in the liquid flow direction and curved on the downstream side in the liquid flow direction, but this is not limiting. For example, the side surface 511 of the diverter 51 may be configured flat or curved throughout the entire length in the liquid flow direction.

[0034] In this embodiment, the rectifying member 5 is provided between the movement area MA of the valve element 3 and the downstream end 41 of the air supply pipe 4 in the flow direction of the air AF, and is configured not to interfere with the valve element 3 over the entire movement area MA of the valve element 3. By providing the rectifying member 5 between the movement area MA of the valve element 3 and the downstream end 41 of the air supply pipe 4 in the flow direction of the air AF, it is possible to prevent the moving valve element 3 from interfering with the rectifying member 5.

[0035] Specifically, the flow rectifying member 5 has a shape in which a portion corresponding to the movement area of ​​the valve disc 3 is cut out. That is, the flow rectifying member 5 has a cutout portion 512 cut out in a portion corresponding to the movement area of ​​the valve disc 3. The flow diverting section 51 is configured to have the cutout portion 512, so that it can divert the liquid while preventing interference with the valve disc 3. In this embodiment, the cutout surface that forms the cutout portion 512 has a shape that follows the trajectory of the valve disc 3. Furthermore, the cutout surface is configured to have a gap between it and the movement area of ​​the valve disc 3. This makes it possible to more reliably prevent interference between the valve disc 3 and the flow diverting section 51.

[0036] In this embodiment, the height H of the flow dividing section 51 (the length of protrusion from the inner wall surface 242 of the valve box 2 radially inward of the valve box 2, see FIG. 4(b)) is set to a height that enables the flow dividing section 51 to have the above-mentioned flow dividing function. The height H of the flow dividing section 51 can be set, for example, in accordance with the distance between the valve disc 3 and the inner wall surface 242 of the upper part of the valve box 2, or the size of the cross section of the liquid flowing from the gap G2 between the valve disc 3 and the inner wall surface 242 of the valve box 2 toward the air supply pipe 4.

[0037] In this embodiment, the valve 1 is an eccentric valve as described above (see FIGS. 1, 2, and 5 to 7). In this embodiment, when the valve disc 3 partially opens the opening 21 on one end of the valve box 2 (see FIGS. 2, 5, and 6), the rectifying member 5 is configured to rectify the flow LF of liquid that flows in from the opening 21 on one end and flows toward the air supply pipe 4 through the gap G2 between the valve disc 3 and the inner wall surface 242 of the valve box 2. By configuring the rectifying member 5 to rectify this type of liquid flow LF, in a valve 1 of the type in which liquid flows through the gap G2 between the valve disc 3 and the inner wall surface 242 of the valve box 2, it is possible to prevent the flow of air AF from the air supply pipe 4 into the valve box 2 from being obstructed by the liquid flow LF. In addition, in this type of valve 1, it is possible to prevent the flow of liquid AF that has flowed into the valve box 2 from the air supply pipe 4 from being obstructed by the liquid flow LF from being supplied to an area where a pressure drop of the liquid is likely to occur.

[0038] In this embodiment, the rectifying member 5 is provided between the movement area MA of the valve disc 3 and the downstream end 41 of the air supply pipe 4 in the flow direction of the air AF (see FIGS. 1, 2, 5 to 7). The movement area MA of the valve disc 3 is the trajectory of change in posture or movement of the valve disc 3 when the valve disc 3 transitions the opening 21 on one end side between a fully closed state and a fully open state. With the configuration in which the rectifying member 5 is provided between the movement area MA of the valve disc 3 and the downstream end 41 of the air supply pipe 4 in the flow direction of the air AF (upstream side of the air supply pipe 4 in the flow direction of the liquid), liquid that flows into the valve box 2 from the gap G1 between the valve disc 3 and the opening 21 on one end side is likely to be rectified by the rectifying member 5 before reaching the vicinity of the air supply pipe 4. This more reliably prevents the liquid that flows into the valve box 2 from the gap G1 between the valve disc 3 and the opening 21 on one end side from colliding with the air AF that flows into the valve box 2 from the air supply pipe 4.

[0039] In this embodiment, the movement area MA is the locus of change in the attitude or movement of the valve disc 3 when the valve disc 3 rotates around the rotation axis 31. Specifically, it is the locus of change in the attitude of the valve disc 3 when the valve disc 3 transitions (see FIGS. 2, 5, and 6) between a state in which the reference direction D3 of the valve disc 3 is on the axis 23 of the valve box 2 (fully closed state, see FIG. 1) and a state in which the reference direction D3 of the valve disc 3 approaches parallel to the axis-orthogonal direction D2 of the valve box 2 (fully open state (for example, the angle between the reference direction D3 and the axis-orthogonal direction D2 is 0° to 20°), see FIG. 7). In this embodiment, the valve disc 3 rotates upward (toward the air supply pipe 4). As a result, with regard to the gap G1 between the valve disc 3 and the opening 21 on one end side, the gap G12 between the valve disc 3 and the upper part of the opening 21 on one end side is smaller than the gap G11 between the valve disc 3 and the lower part of the opening 21 on one end side. Therefore, the flow area of ​​the liquid passing through the gap G12 between the valve body 3 and the upper part of the opening 21 on the one end side is smaller than the flow area of ​​the liquid passing through the gap G11 between the valve body 3 and the lower part of the opening 21 on the one end side. Therefore, even a small flow rectifying member 5 can rectify the flow of the liquid passing through the gap G12 between the valve body 3 and the upper part of the opening 21 on the one end side. This allows the flow rectifying member 5 to be configured compactly. Furthermore, by configuring the flow rectifying member 5 compactly, the resistance of the flow rectifying member 5 to the flow of the liquid can be reduced. This makes it possible to suppress a decrease in flow rate due to the provision of the flow rectifying member 5.

[0040] The valve element 3 is not limited to a configuration in which it rotates upward (toward the air supply pipe 4). The valve element 3 may also be configured to rotate downward (toward the opposite side from the side in which the air supply pipe 4 is located). In this case, with regard to the gap G1 between the valve element 3 and the opening 21 at one end, the gap G12 between the valve element 3 and the upper part of the opening 21 at one end is larger than the gap G11 between the valve element 3 and the lower part of the opening 21 at one end. Therefore, the flow area of ​​the liquid passing through the gap G12 between the valve element 3 and the upper part of the opening 21 at one end is larger than the flow area of ​​the liquid passing through the gap G11 between the valve element 3 and the lower part of the opening 21 at one end. For this reason, by providing a flow straightening member 5 that is larger than the flow straightening member 5 in the examples shown in FIGS. 1, 2, 5, and 6, the flow of the liquid passing through the gap G12 between the valve element 3 and the upper part of the opening 21 at one end can be straightened.

[0041] In the above-described valve 1, the flow rectifying member 5 is provided on the inner wall surface 242 of the valve box 2 in a section between the valve disc 3 and the air supply pipe 4, but this is not limited thereto. For example, in a case where the air supply pipe 4 is connected to a through hole 241 formed in the peripheral wall 24 of the valve box 2, a flow rectifying member (not shown) may be provided so as to protrude from the through hole 241 radially inward of the valve box 2. This flow rectifying member is configured to rectify the flow of liquid so that the liquid that flows into the valve box 2 from the gap G1 between the opening 21 on the one end side and the valve disc 3 avoids the flow area DA of the air AF that flows into the valve box 2 from the air supply pipe 4. Specifically, the flow rectifying member is, for example, a plate-shaped member with a V-shaped cross section that widens in a V-shape from the upstream side D11 to the downstream side D12 in the liquid flow direction when viewed from the radial center side of the valve box 2. This flow rectifying member can rectify (divide) the liquid on its upstream surface in the liquid flow direction. This flow straightening member has an open surface on the upstream side in the liquid flow direction, but is not limited to this. For example, the flow straightening member may be a generally cylindrical member with a V-shaped cross section on the upstream side D11 in the liquid flow direction and a closed downstream side D12. Because this flow straightening member is a tubular member with a closed downstream side D12, it can guide the air AF along the axial direction of the pipe while straightening (dividing) the liquid on the surface on the upstream side D11 in the liquid flow direction. Therefore, the flow area DA for the air AF can be more reliably secured compared to when the downstream side D12 is not closed.

[0042] As described above, in the valve 1 according to this embodiment, the rectifying member 5 is configured to rectify the flow of liquid such that the liquid that has flowed into the valve box 2 from the gap G1 between the opening 21 on one end side of the valve box 2 and the valve disc 3 flows away from the air flow area DA through which air has flowed into the valve box 2 from the air supply pipe 4. With this configuration, the rectifying member 5 can ensure the air flow area DA within the valve box 2. This can prevent the liquid flow from colliding with air attempting to flow from the air supply pipe 4 into the valve box 2, and can also prevent the liquid flow from colliding with air supplied into the valve box 2 from the air supply pipe 4. This can stably supply air from the air supply pipe 4 into the valve box 2, improving the efficiency of cavitation suppression.

[0043] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Note that the above-described embodiments mainly describe the invention having the following configurations.

[0044] (1) A cylindrical valve body having an inlet pipe connected to an opening at one axial end thereof and an outlet pipe connected to an opening at the other axial end thereof; a valve body that adjusts the opening degree of the opening on the one end side within the valve box; an air supply pipe for supplying air into the valve body; a flow rectifying member provided in the valve box; Equipped with The rectifying member is configured to rectify the flow of the liquid that has flowed into the valve body from the gap between the opening on the one end side and the valve body so that the liquid flows away from a flow area of ​​air that has flowed into the valve body from the air supply pipe. Valve with rectifying function.

[0045] (2) The flow area is an area extending from a downstream end of the air supply pipe in the air flow direction toward the valve body. The valve with rectifying function described in (1).

[0046] (3) The flow straightening member is configured to divide the liquid that has flowed into the valve body from the gap between the opening on the one end side and the valve body into a flow on one side and a flow on the other side of the flow area, upstream of the flow area in the liquid flow direction. A valve with a rectifying function according to (1) or (2).

[0047] (4) The valve element includes a rotary shaft located downstream of the opening on the one end side in the direction of flow of the liquid, and a valve body that opens and closes the opening on the one end side, and the valve element is an eccentric valve in which the rotary shaft is located downstream of the valve body in the direction of flow of the liquid, When the valve disc is in a state where the opening on the one end side is partially open, the rectifying member is configured to rectify the flow of liquid that flows in from the opening on the one end side and flows through a gap between the valve disc and an inner wall surface of the valve body toward the air supply pipe. The valve with rectifying function according to any one of (1) to (3).

[0048] (5) The rectifying member is provided between a movement area of ​​the valve body and a downstream end of the air supply pipe in the air flow direction. The valve with rectifying function according to any one of (1) to (4). [Explanation of symbols]

[0049] 1. Valve with rectifying function 2 Valve box 21 Opening on one end 22 Opening on the other end 23 axis 24 Peripheral wall 241 Through hole 242 Inner wall surface 3 Valve body 31 Rotation axis 32 Valve body 33 Arm section 4 Air supply pipe 41 Downstream end 5 Straightening member 51 Diversion section 511 Side wall 512 Notch 6 Inlet piping 7 Outlet piping AF Air flow CL V-shaped center line D1 Axial direction of valve body D11 Upstream side in the direction of liquid flow D12 Downstream in the direction of liquid flow D2: Direction perpendicular to the axial direction of the valve body (direction perpendicular to the axis) D3 Reference direction of valve disc DA Air flow area MA Valve disc movement area LF Liquid Flow LF1 One-side flow LF2 Other side flow G1: Gap between the valve body and the opening on one end G11 Gap between the valve body and the bottom of the opening on one end (lower gap) G12 Gap between the valve body and the top of the opening on one end (upper gap) G2: Gap between the valve disc and the inner wall of the valve body H Height of the flow straightening member

Claims

1. a cylindrical valve body having an inlet pipe connected to an opening at one axial end thereof and an outlet pipe connected to an opening at the other axial end thereof; a valve body that adjusts the opening degree of the opening on the one end side within the valve box; an air supply pipe for supplying air into the valve body; a flow rectifying member provided in the valve box; Equipped with The rectifying member is configured to rectify the flow of the liquid that has flowed into the valve body from the gap between the opening on the one end side and the valve body so that the liquid flows away from a flow area of ​​air that has flowed into the valve body from the air supply pipe. Valve with rectifying function.

2. the flow area is an area extending from a downstream end of the air supply pipe in the air flow direction toward the valve body, The valve with rectifying function according to claim 1.

3. The flow straightening member is configured to divide the liquid that has flowed into the valve body from a gap between the opening on the one end side and the valve body into a flow on one side and a flow on the other side sandwiching the flow area, upstream of the flow area in the liquid flow direction. The valve with rectifying function according to claim 1.

4. the valve element includes a rotary shaft located downstream of the opening on the one end side in the direction of flow of the liquid, and a valve body that opens and closes the opening on the one end side, and the valve element is an eccentric valve in which the rotary shaft is located downstream of the valve body in the direction of flow of the liquid, When the valve disc is in a state where the opening on the one end side is partially open, the rectifying member is configured to rectify the flow of liquid that flows in from the opening on the one end side and flows through a gap between the valve disc and an inner wall surface of the valve body toward the air supply pipe. The valve with rectifying function according to claim 1.

5. the flow straightening member is provided between a movement area of ​​the valve body and a downstream end of the air supply pipe in the air flow direction. The valve with rectifying function according to claim 1.

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